Soluble organic nitrogen （SON） is recognized as a sensitive indicator of soil nitrogen status. The present work was conducted in the temperate forests of northeast China where soils are typically characterized by hi...Soluble organic nitrogen （SON） is recognized as a sensitive indicator of soil nitrogen status. The present work was conducted in the temperate forests of northeast China where soils are typically characterized by high organic matter and high organic nitrogen content, and soil sampling was made in early spring just after the freeze-thaw period. The water extracted SON pools in the organic layer of forest soils were measured within the range from 156.0 mg·kg^-1 to 292.6 mg·kg^-1, a similar magnitude of salt solution extracted SON pools reported in literatures. However, the water soluble SON pools in 0-15 cm mineral soils in present study were much higher （3-10 times） than any other reports, ranging from 58.6 mg·kg^-1 to 125.2 mg·kg^-1. Water soluble SON varied markedly among the soils under different forests and at different sites. The SON in water extracts were positively and significantly correlated to soil organic matter and total nitrogen contents, but negatively correlated to microbial biomass nitrogen （MBN）. The reasons of the abnormally large SON pools and the negative correlations between SON and MBN in the 0-15cm mineral soils in this study were specially discussed.展开更多
含氮化合物是大气细颗粒物(PM_(2.5))的重要组分,其中含氮有机物是含氮组分的重要存在形式,对陆地和水生生态系统影响较大.于2015年4月、7月和10月分别采集了金华市3个具有代表性站点的PM_(2.5)样品,分析了其中水溶性有机氮(water-solub...含氮化合物是大气细颗粒物(PM_(2.5))的重要组分,其中含氮有机物是含氮组分的重要存在形式,对陆地和水生生态系统影响较大.于2015年4月、7月和10月分别采集了金华市3个具有代表性站点的PM_(2.5)样品,分析了其中水溶性有机氮(water-soluble organic nitrogen,WSON)的质量浓度分布及季节变化特征.结果表明:金华市PM2.5中WSON质量浓度范围为0.06～6.90μg/m^3,平均1.90μg/m^3,对水溶性总氮(water-soluble total nitrogen,WSTN)的平均贡献率为31%.WSON的质量浓度分布具有明显的季节变化特征:秋季较高,夏季较低,而在夏季WSON对WSTN的贡献率最高.金华市PM_(2.5)中WSON的主要来源可能是含氮前体物在大气中的二次转化以及生物质燃烧活动.展开更多
On the basis of referring plenty of literatures, we summarized the research advance in effects of nitrogen on the internal quality of peach fruit. Most studies have shown that proper nitrogen application can improve i...On the basis of referring plenty of literatures, we summarized the research advance in effects of nitrogen on the internal quality of peach fruit. Most studies have shown that proper nitrogen application can improve internal quality of fruit, and excessive nitrogen application can reduce soluble solid and sugar contents of fruit, increase organic acid content, reduce fruit aroma, increase protein and amino acid contents, and increase or reduce vitamin C content. Relevant issues were discussed.展开更多
Dissolved organic nitrogen(DON) has attracted much attention in drinking water treatment due to its potential to produce nitrogenous disinfection by-products(N-DBPs). This work was designed to explore the transformati...Dissolved organic nitrogen(DON) has attracted much attention in drinking water treatment due to its potential to produce nitrogenous disinfection by-products(N-DBPs). This work was designed to explore the transformation and fate of DON and dissolved inorganic nitrogen(DIN) in drinking water treatment. The changes of DON and formation of N-DBPs were evaluated along the water treatment route(i.e., pre-ozonation and biologicalcontact oxidation, delivery pipes’ transportation, coagulation-sedimentation, sand filtration, post-ozonation, biological activated carbon, ultrafiltration and disinfection) of drinking water treatment plant(DWTP). The transformation mechanism of DON was comprehensively investigated by molecular weight fractionation, three-dimensional fluorescence, LCOCD(Liquid Chromatography-Organic Carbon Detection), total free amino acids. A detailed comparison was made between concentrations and variations of DON and DIN affected by seasons in the drinking water treatment. Regardless of seasonal variation in raw water concentration, the DON removal trends between different treatment processes remain constant in the present study. Compared to other treatment processes, pre-ozonation and coagulation-sedimentation exhibited the dominant DON removal in different seasons, i.e.,11.13%-14.45% and 14.98%-22.49%, respectively. Contrary, biological-contact oxidation and biological activated carbon negatively impacted the DON removal, in which DON increased by 1.76%-6.49% in biological activated carbon. This may be due to the release of soluble microbial products(SMPs) from bacterial metabolism, which was further validated by the rise of biopolymers in LC-OCD.展开更多
森林生态系统作为生物圈的重要组成部分,维持着全球植被碳库的86%和土壤碳库的40%（Houghton et al.,2001;胡会峰等,2006）。因此,森林在调节全球气候、维持全球碳平衡方面起着非常重要的作用（Fang et al.,2001;Woodbury et al.,2007;H...森林生态系统作为生物圈的重要组成部分,维持着全球植被碳库的86%和土壤碳库的40%（Houghton et al.,2001;胡会峰等,2006）。因此,森林在调节全球气候、维持全球碳平衡方面起着非常重要的作用（Fang et al.,2001;Woodbury et al.,2007;Hu et al.,2008）。然而,展开更多
基金National Nature Science Foundation of China (30571476, 30771703)
文摘Soluble organic nitrogen （SON） is recognized as a sensitive indicator of soil nitrogen status. The present work was conducted in the temperate forests of northeast China where soils are typically characterized by high organic matter and high organic nitrogen content, and soil sampling was made in early spring just after the freeze-thaw period. The water extracted SON pools in the organic layer of forest soils were measured within the range from 156.0 mg·kg^-1 to 292.6 mg·kg^-1, a similar magnitude of salt solution extracted SON pools reported in literatures. However, the water soluble SON pools in 0-15 cm mineral soils in present study were much higher （3-10 times） than any other reports, ranging from 58.6 mg·kg^-1 to 125.2 mg·kg^-1. Water soluble SON varied markedly among the soils under different forests and at different sites. The SON in water extracts were positively and significantly correlated to soil organic matter and total nitrogen contents, but negatively correlated to microbial biomass nitrogen （MBN）. The reasons of the abnormally large SON pools and the negative correlations between SON and MBN in the 0-15cm mineral soils in this study were specially discussed.
文摘含氮化合物是大气细颗粒物(PM_(2.5))的重要组分,其中含氮有机物是含氮组分的重要存在形式,对陆地和水生生态系统影响较大.于2015年4月、7月和10月分别采集了金华市3个具有代表性站点的PM_(2.5)样品,分析了其中水溶性有机氮(water-soluble organic nitrogen,WSON)的质量浓度分布及季节变化特征.结果表明:金华市PM2.5中WSON质量浓度范围为0.06～6.90μg/m^3,平均1.90μg/m^3,对水溶性总氮(water-soluble total nitrogen,WSTN)的平均贡献率为31%.WSON的质量浓度分布具有明显的季节变化特征:秋季较高,夏季较低,而在夏季WSON对WSTN的贡献率最高.金华市PM_(2.5)中WSON的主要来源可能是含氮前体物在大气中的二次转化以及生物质燃烧活动.
基金Supported by Key Technology R&D Program of Hebei Province(16226313D-3)Innovation Project of Hebei Academy of Agriculture and Forestry Sciences(2019-3-5-1,F18C10001,2018100201)Shijiazhuang Comprehensive Experimental Station of China Agro-industry(Peach Industry)Research System(CARS-31-Z-2)
文摘On the basis of referring plenty of literatures, we summarized the research advance in effects of nitrogen on the internal quality of peach fruit. Most studies have shown that proper nitrogen application can improve internal quality of fruit, and excessive nitrogen application can reduce soluble solid and sugar contents of fruit, increase organic acid content, reduce fruit aroma, increase protein and amino acid contents, and increase or reduce vitamin C content. Relevant issues were discussed.
文摘Dissolved organic nitrogen(DON) has attracted much attention in drinking water treatment due to its potential to produce nitrogenous disinfection by-products(N-DBPs). This work was designed to explore the transformation and fate of DON and dissolved inorganic nitrogen(DIN) in drinking water treatment. The changes of DON and formation of N-DBPs were evaluated along the water treatment route(i.e., pre-ozonation and biologicalcontact oxidation, delivery pipes’ transportation, coagulation-sedimentation, sand filtration, post-ozonation, biological activated carbon, ultrafiltration and disinfection) of drinking water treatment plant(DWTP). The transformation mechanism of DON was comprehensively investigated by molecular weight fractionation, three-dimensional fluorescence, LCOCD(Liquid Chromatography-Organic Carbon Detection), total free amino acids. A detailed comparison was made between concentrations and variations of DON and DIN affected by seasons in the drinking water treatment. Regardless of seasonal variation in raw water concentration, the DON removal trends between different treatment processes remain constant in the present study. Compared to other treatment processes, pre-ozonation and coagulation-sedimentation exhibited the dominant DON removal in different seasons, i.e.,11.13%-14.45% and 14.98%-22.49%, respectively. Contrary, biological-contact oxidation and biological activated carbon negatively impacted the DON removal, in which DON increased by 1.76%-6.49% in biological activated carbon. This may be due to the release of soluble microbial products(SMPs) from bacterial metabolism, which was further validated by the rise of biopolymers in LC-OCD.
文摘森林生态系统作为生物圈的重要组成部分,维持着全球植被碳库的86%和土壤碳库的40%（Houghton et al.,2001;胡会峰等,2006）。因此,森林在调节全球气候、维持全球碳平衡方面起着非常重要的作用（Fang et al.,2001;Woodbury et al.,2007;Hu et al.,2008）。然而,
